In the first half of this year, advertisers in the UK spent £699m on video advertising – a year-on-year increase of 46%, the latest biannual Digital Adspend report has found.

Meanwhile, spend on banner ads increased by under 2% to £685m.

Video now accounts for over a third ( 35%) of all display ad spend, and is the fastest-growing advertising format.

Within video advertising, spend on outstream – that is, video adverts that appear on a page, typically between paragraphs of text, as opposed to before video content – and social in-feed accounted for over half ( 52%) of all video spend, at £363m. This format has now overtaken spend on pre- and post-roll ads, which account for 44% (£309m).

The time spent watching short online video clips has increased from 51 minutes in 2014 to 2 hrs 21 minutes per week in 2017, according to a YouGov survey of over 2,000 adults.

The IAB study also found that digital display advertising as a whole grew by 18% to £2bn. Overall digital ad spend, also incorporating search and classifieds, grew 13.8% to £5.56bn in the first six months of the year.

The IAB’s chief executive Jon Mew said: “The time people spend watching online video has grown tremendously over the last few years, so it’s little wonder that video is now the fastest-growing ad format as advertisers look to tap into the changing way people consume content.”